Vol 33, No 4 (2026)

Despite the existing data on dioxin hepatotoxicity, information on the role of gut microbiota and intersystem interactions in the gut-liver axis remains fragmented. Mechanisms linking direct toxic hepatocyte damage, bile outflow disorders (cholestasis) , and aryl hydrocarbon receptor (AhR)–dependent immune modulation to changes in the gut microbiota and progression of fatty liver degeneration lack sufficient systematization. This necessitates a comprehensive reinterpretation of existing data and the identification of gaps in understanding the microbiome-dependent mechanisms of chronic hepatotoxicity.

This study aimed to analyze current data on the role of gut microbiota in the development of diffuse liver pathology under chronic dioxin exposure, including the contributions of oxidative stress, lipid peroxidation processes, and immune disorders.

The scientific publications for this review were searched and analyzed in both Russian and international reference and bibliographic databases. These included the Russian Science Citation Index, along with international databases such as PubMed, Scopus, Web of Science, and Google Scholar, covering the past 10 years. Using search queries dioxins and dioxin-like compounds, a pool of publications was formed, and works on the toxicokinetics of persistent organic pollutants were selected.

Analysis of modern publications devoted to the role of gut microbiota in the pathogenesis of dioxin hepatotoxicity indicates that the liver is one of the key target organs during chronic exposure to these persistent organic pollutants. Aggregated data confirm the leading role of the gut-liver axis in the development of diffuse liver pathology, including the mechanisms of interaction between its components, changes in microbiota, barrier function impairments, immunoinflammatory reactions, and activation of signaling pathways involved in the development of hepatic injuries. The analysis allows for clarifying modern concepts on pathogenetic mechanisms and expanding approaches to the diagnosis of diffuse liver diseases during chronic dioxin exposure.

Fatty liver degeneration under the influence of hepatotoxicants results from the interaction of xenobiotics with liver enzymes, microbiota, and immune mechanisms. Toxicants often transform into more harmful metabolites that enhance oxidative stress and hepatocyte damage. Impaired microbiota and bile acid metabolism intensify inflammation and fibrosis. Persistent pollutants activate AhR and alter cytochrome P450 activity, which contributes to the formation of chronic toxic liver damage.

The appearance of the skin and its appendages, including eyelashes and eyebrows, is an important component of physical and psychosocial well-being and substantially affects quality of life. The condition of eyelashes and eyebrows is determined by a complex interplay of endogenous and exogenous factors, including environmental exposure, systemic diseases, and cosmetic procedures. Interest has recently grown in cosmetic products aimed at stimulating growth and improving the quality of eyelashes and eyebrows; however, the evidence base supporting the effectiveness of many active ingredients remains limited. This narrative review summarizes current research on the potential of dihydroquercetin in combination with adenosine, kopyrrol, and several other compounds in cosmetic formulations intended to promote eyelash and eyebrow growth. We focus on the challenges of low solubility and bioavailability of dihydroquercetin and on current strategies for overcoming these limitations, including cyclodextrin encapsulation and other pharmaceutical and technological approaches. We present data on the molecular mechanisms underlying hair growth stimulation, including activation of the Wnt/β-catenin, AKT, and MAPK/CREB signaling pathways and induction of growth factors. We also review clinical and experimental studies evaluating adenosine, kopyrrol, arabinogalactan, and peptides for hair, eyebrow, and eyelash growth. Based on the analyzed data, we discuss the potential for synergistic effects of combined formulations, and outline key directions for further experimental and clinical research needed to substantiate the efficacy and safety of such cosmetic products in reducing the impact of adverse environmental factors and preserving aesthetic appearance, quality of life, satisfaction with appearance, and social functioning.

BACKGROUND: Studying the hormonal profile of the same individuals under contrasting seasonal changes of climate and geophysical factors in Subarctic allows effective detection of periods of reduced adaptive capabilities of the endocrine system, which helps timely correct pre-pathological conditions.

AIM: This work aimed to study the influence of seasonal dynamics of meteorological factors of the temperate-continental climate of Subarctic on serum levels of thyroid and sex hormones.

METHODS: An analytical, prospective, uncontrolled study included 40 clinically healthy residents of Arkhangelsk (20 men and 20 women). Blood samples were collected quarterly for a year. Correlation between hormonal and climatic indicators was assessed using Spearman’s correlation coefficient.

RESULTS: In the examined men, statistically significant variability was detected in the levels of total fractions of iodothyronines, thyroxine-binding globulin, estradiol, and antisperm antibodies, correlating with climate factors. Levels of free iodothyronine fractions in men show a low amplitude in their annual rhythm and likely do not depend on seasonal factors. Conversely, in women, free fraction levels correlate positively with day length, whereas free thyroxine levels correlate negatively with air humidity. Overall, thyroid function parameters, regardless of sex, demonstrate a direct correlation with day length and air temperature, and an inverse correlation with atmospheric pressure and humidity. Unlike in women, circannual differences in estradiol and antisperm antibody levels were found in men, comparable to changes in photoperiod, fluctuations in atmospheric pressure, and air temperature.

CONCLUSION: The findings indicate that the summer period with a long photoperiod is associated with increased activity of the pituitary–thyroid axis, whereas ovarian function does not show a significant dependence on day length.

BACKGROUND: Monitoring the safety of food products from Pacific salmon (Oncorhynchus spp.), which are a key commercial species and an important component of the Far Eastern Russian diet, is conducted in Russia in accordance with the requirements of the Customs Union Technical Regulation 021/2011 On Food Safety. Prospective studies, including those assessing cadmium (Cd) and lead (Pb) levels in various organs and tissues of salmon, represent a relevant research direction.

AIM: This study aimed to assess toxic elements (Cd, Pb) levels in Pacific salmons from the Sea of Okhotsk and the Bering Sea.

METHODS: Organ samples (muscles, liver, gonads) of Pacific salmons (pink salmon Oncorhynchus gorbuscha, chum salmon O. keta, sockeye salmon O. nerka) were collected in 2018 and 2021 from water bodies and streams of Sakhalin and Iturup islands, as well as from Avacha and Kamchatka bays. The content of Cd and Pb was determined by atomic absorption spectrometry. The reliability of the results was ensured by using international standard reference materials.

RESULTS: A total of 213 samples were analyzed, with Cd and Pb detected in each. Exceeding the current Russian hygienic standards was recorded only in the liver for cadmium (17.8% of samples) and lead (3.6% of samples). High cadmium values were noted in the liver of chum salmon from Iturup Island (1.226 ± 0.36 mg/kg in Blagodatnoye Lake, 0.723 ± 0.298 mg/kg at Reidovy Salmon Hatchery), as well as in samples from the southwestern coast of Sakhalin Island (0.855 ± 0.645 mg/kg), in sockeye salmon from Avacha Bay (1.31 ± 0.56 mg/kg) and Kamchatka Bay (0.82 ± 0.65 mg/kg). Elevated values for lead were identified in the liver of chum salmon from Sakhalin Island (1.176 ± 0.361 mg/kg at Firsovka Salmon Hatchery).

CONCLUSION: The content of cadmium and lead in the muscle tissue of Pacific salmon (pink, chum, sockeye) from the Sea of Okhotsk and the Bering Sea does not exceed the current Russian standards. However, for the export of fish products, control of toxic element content is required to comply with international standards. Species and organ specificity of metal accumulation was identified.